Ottoman Gold Ring Featuring an Agate Stone - OS.175, Origin: Turkey, Circa: 16 th Century AD to 19 th Century AD, Collection: Jewelry, Style: Ottoman, Medium: Agate, Gold. At its height, the Ottoman Empire was one of the world’s great powers, controlling much of southeastern Europe, North Africa, and the Middle East. The roots of the Ottoman Empire can be traced back to the migration of Turkic tribes from Central Asia into Anatolia. Expert horsemen, fierce and highly mobile, these armies encountered little resistance as they moved westward and settled, eventually uniting under the banner of the Seljuk Empire. Back in the East, the rise of the Mongols sent progressive waves of Turkic refugees fleeing the armies of the Khan. The turmoil created by this influx of people, as well as direct confrontations with the Mongols themselves, eventually resulted in the dissolution of the Seljuk Empires into several fractured independent states. One of these states, ruled by Osman I, from whom the word Ottoman is derived, would become the Ottoman Empire.